Detection of anti-Leptospira spp., anti-Brucella spp., and anti-Toxoplasma gondii antibodies in stray dogs / Detecção de anticorpos anti-Leptospira spp., anti-Brucella spp., and anti-Toxoplasma gondii em cães errantes

Dogs can act as intermediary hosts, reservoirs, and sentinel animals for zoonotic diseases such as brucellosis, toxoplasmosis and leptospirosis, and human contact with domestic animals can spread these infections. These diseases are globally distributed, and are a uniquely severe health issue, since they can infect a great range of animals, including humans. The purpose of this work was to determine the prevalence of anti-Leptospira spp., anti-Brucella spp., and anti-Toxoplasma gondii antibodies in stray dogs. Blood samples were collected from 181 stray dogs and used for serological diagnosis. Of the analyzed samples, 36.46%, 16.57%, and 9.39% were positive for T. gondii, Leptospira spp., and B. canis. The results indicate that these zoonotic diseases are highly prevalent in stray dogs in the northwestern region of the state of Paraná. The high infection rates for these zoonotics in the canine population is an indication that the environment is contaminated with a variety of different microorganisms, exposing both humans and dogs to different sources of infection.

O contato do homem com alguns animais domésticos faz com que algumas zoonoses como brucelose, toxoplasmose e leptospirose, tornem-se infecções importantes e, com isso os cães atuam como hospedeiros intermediários, reservatórios e animais sentinelas para estas infecções. Essas enfermidades tem distribuição mundial, e é um grave problema de saúde pública, podendo infectar uma grande variedade de animais, entres os quais, se destacam o cão e o homem. O objetivo deste trabalho foi detectar a ocorrência de anticorpos contra Leptospira spp., Brucella spp. eToxoplasma gondii em cães errantes Amostras de sangue colheram amostras de sangue de 181 cães errantes para a realização dos diagnósticos sorológicos. Das amostras analisadas, 36,46% foram reagentes para Tgondii, 16,57% para Leptospira spp. e9,39% para Brucella canis.A partir dos resultados obtidos no presente trabalho, verificou-se que essas zoonoses apresentam elevadaprevalência nos cães errantes do estudo. O elevado índice de infecção da população canina para estas zoonoses, torna-seum indicativo de que o ambiente está contaminado com diferentes micro-organismos representando um problema para a saúde única, uma vez que tanto o homem como o cão estão expostos a diferentes fontes de infecção.

Detection of anti-Leptospira spp., anti-Brucella spp., and anti-Toxoplasma gondii antibodies in stray dogs / Detecção de anticorpos anti-Leptospira spp., anti-Brucella spp., and anti-Toxoplasma gondii em cães errantes

Dogs can act as intermediary hosts, reservoirs, and sentinel animals for zoonotic diseases such as brucellosis, toxoplasmosis and leptospirosis, and human contact with domestic animals can spread these infections. These diseases are globally distributed, and are a uniquely severe health issue, since they can infect a great range of animals, including humans. The purpose of this work was to determine the prevalence of anti-Leptospira spp., anti-Brucella spp., and anti-Toxoplasma gondii antibodies in stray dogs. Blood samples were collected from 181 stray dogs and used for serological diagnosis. Of the analyzed samples, 36.46%, 16.57%, and 9.39% were positive for T. gondii, Leptospira spp., and B. canis. The results indicate that these zoonotic diseases are highly prevalent in stray dogs in the northwestern region of the state of Paraná. The high infection rates for these zoonotics in the canine population is an indication that the environment is contaminated with a variety of different microorganisms, exposing both humans and dogs to different sources of infection.(AU)

O contato do homem com alguns animais domésticos faz com que algumas zoonoses como brucelose, toxoplasmose e leptospirose, tornem-se infecções importantes e, com isso os cães atuam como hospedeiros intermediários, reservatórios e animais sentinelas para estas infecções. Essas enfermidades tem distribuição mundial, e é um grave problema de saúde pública, podendo infectar uma grande variedade de animais, entres os quais, se destacam o cão e o homem. O objetivo deste trabalho foi detectar a ocorrência de anticorpos contra Leptospira spp., Brucella spp. eToxoplasma gondii em cães errantes Amostras de sangue colheram amostras de sangue de 181 cães errantes para a realização dos diagnósticos sorológicos. Das amostras analisadas, 36,46% foram reagentes para Tgondii, 16,57% para Leptospira spp. e9,39% para Brucella canis.A partir dos resultados obtidos no presente trabalho, verificou-se que essas zoonoses apresentam elevadaprevalência nos cães errantes do estudo. O elevado índice de infecção da população canina para estas zoonoses, torna-seum indicativo de que o ambiente está contaminado com diferentes micro-organismos representando um problema para a saúde única, uma vez que tanto o homem como o cão estão expostos a diferentes fontes de infecção.(AU)

Proinflammatory response of canine trophoblasts to Brucella canis infection.

Brucella canis infection is an important cause of late-term abortion in pregnant bitches. The pathophysiological mechanisms leading to B. canis-induced abortion are unknown, but heavily infected trophoblasts are consistently observed. As trophoblasts responses to other pathogens contribute to placental inflammation leading to abortion, the aim of the present study was to characterize the cytokine response of canine trophoblasts to B. canis infection. To achieve this, trophoblasts isolated from term placenta of healthy female dogs were infected with B. canis, culture supernatants were harvested for cytokine determinations, and the load of intracellular viable B. canis was determined at different times post-infection. Additionally, cytokine responses were assessed in non-infected trophoblasts stimulated with conditioned media (CM) from B. canis-infected canine monocytes and neutrophils. Finally, cytokine response and bacteria replication were assessed in canine placental explants infected ex vivo. B. canis successfully infected and replicated in primary canine trophoblasts, eliciting an increase in IL-8 and RANTES (CCL5) secretion. Moreover, the stimulation of trophoblasts with CM from B. canis-infected monocytes and neutrophils induced a significant increase in IL-8, IL-6 and RANTES secretion. B. canis replication was confirmed in infected placental explants and the infection elicited an increased secretion of TNF-α, IL-8, IL-6 and RANTES. This study shows that canine trophoblasts produce proinflammatory cytokines in response to B. canis infection and/or to stimulation with factors produced by infected monocytes and neutrophils. These cytokines may contribute to placental inflammation leading to abortion in B. canis-infected pregnant bitches.

Brucella canis is an intracellular pathogen that induces a lower proinflammatory response than smooth zoonotic counterparts.

Canine brucellosis caused by Brucella canis is a disease of dogs and a zoonotic risk. B. canis harbors most of the virulence determinants defined for the genus, but its pathogenic strategy remains unclear since it has not been demonstrated that this natural rough bacterium is an intracellular pathogen. Studies of B. canis outbreaks in kennel facilities indicated that infected dogs displaying clinical signs did not present hematological alterations. A virulent B. canis strain isolated from those outbreaks readily replicated in different organs of mice for a protracted period. However, the levels of tumor necrosis factor alpha, interleukin-6 (IL-6), and IL-12 in serum were close to background levels. Furthermore, B. canis induced lower levels of gamma interferon, less inflammation of the spleen, and a reduced number of granulomas in the liver in mice than did B. abortus. When the interaction of B. canis with cells was studied ex vivo, two patterns were observed, a predominant scattered cell-associated pattern of nonviable bacteria and an infrequent intracellular replicative pattern of viable bacteria in a perinuclear location. The second pattern, responsible for the increase in intracellular multiplication, was dependent on the type IV secretion system VirB and was seen only if the inoculum used for cell infections was in early exponential phase. Intracellular replicative B. canis followed an intracellular trafficking route undistinguishable from that of B. abortus. Although B. canis induces a lower proinflammatory response and has a stealthier replication cycle, it still displays the pathogenic properties of the genus and the ability to persist in infected organs based on the ability to multiply intracellularly.

Immunization with Brucella VirB proteins reduces organ colonization in mice through a Th1-type immune response and elicits a similar immune response in dogs.

VirB proteins from Brucella spp. constitute the type IV secretion system, a key virulence factor mediating the intracellular survival of these bacteria. Here, we assessed whether a Th1-type immune response against VirB proteins may protect mice from Brucella infection and whether this response can be induced in the dog, a natural host for Brucella. Splenocytes from mice immunized with VirB7 or VirB9 responded to their respective antigens with significant and specific production of gamma interferon (IFN-γ), whereas interleukin-4 (IL-4) was not detected. Thirty days after an intraperitoneal challenge with live Brucella abortus, the spleen load of bacteria was almost 1 log lower in mice immunized with VirB proteins than in unvaccinated animals. As colonization reduction seemed to correlate with a Th1-type immune response against VirB proteins, we decided to assess whether such a response could be elicited in the dog. Peripheral blood mononuclear cells (PBMCs) from dogs immunized with VirB proteins (three subcutaneous doses in QuilA adjuvant) produced significantly higher levels of IFN-γ than cells from control animals upon in vitro stimulation with VirB proteins. A skin test to assess specific delayed-type hypersensitivity was positive in 4 out of 5 dogs immunized with either VirB7 or VirB9. As both proteins are predicted to locate in the outer membrane of Brucella organisms, the ability of anti-VirB antibodies to mediate complement-dependent bacteriolysis of B. canis was assessed in vitro. Sera from dogs immunized with either VirB7 or VirB9, but not from those receiving phosphate-buffered saline (PBS), produced significant bacteriolysis. These results suggest that VirB-specific responses that reduce organ colonization by Brucella in mice can be also elicited in dogs.

Evaluation of the efficacy of outer membrane protein 31 vaccine formulations for protection against Brucella canis in BALB/c mice.

Canine brucellosis is an infectious disease caused by the Gram-negative bacterium Brucella canis. Unlike conventional control programs for other species of the genus Brucella, currently there is no vaccine available against canine brucellosis, and preventive measures are simply diagnosis and isolation of infected dogs. New approaches are therefore needed to develop an effective and safe immunization strategy against this zoonotic pathogen. In this study, BALB/c mice were subcutaneously immunized with the following: (i) the recombinant Brucella Omp31 antigen formulated in different adjuvants (incomplete Freund adjuvant, aluminum hydroxide, Quil A, and Montanide IMS 3012 VGPR), (ii) plasmid pCIOmp31, or (iii) pCIOmp31 plasmid followed by boosting with recombinant Omp31 (rOmp31). The immune response and the protective efficacy against B. canis infection were characterized. The different strategies induced a strong immunoglobulin G (IgG) response. Furthermore, spleen cells from rOmp31-immunized mice produced gamma interferon and interleukin-4 (IL-4) after in vitro stimulation with rOmp31, indicating the induction of a mixed Th1-Th2 response. Recombinant Omp31 administered with different adjuvants as well as the prime-boost strategy conferred protection against B. canis. In conclusion, our results suggest that Omp31 could be a useful candidate for the development of a subcellular vaccine against B. canis infection.

[Detection of Brucella canis by immunochromatography method in vague dogs captured in Temuco city, Chile, 2011]. / Detección de Brucella canis por método de inmunocromatografía en perros vagos capturados en la ciudad de Temuco, Chile, 2011.

BACKGROUND: Brucella canis is responsible for brucellosis in dogs, causing reproductive disorders and is considered a zoonoses, as described in several countries. The epidemiological data are scarce in our country. AIM: To determine the prevalence of Brucella canis in vague dogs in Temuco city and housed in the Temuco Kennel. METHODS: Quantitative and cross-section study. We used 400 samples of dogs of both sexes, different ages and mainly mixed race, which were tested by immunochromatography. RESULTS: Antibodies were detected in 4 samples Brucella canis which represented 1% of the population studied, 2 females (0.5%) and 2 males (0.5%). DISCUSSION: We conclude that dogs are infected by B. canis in a low range but remains a risk condition to the health of the human population if not maintained adequate sanitary control of pets, like vague dogs.

[Factors associated with Brucella canis seropositivity in kennels of two regions of Antioquia, Colombia]. / Factores asociados con la seropositividad a Brucella canis en criaderos caninos de dos regiones de Antioquia, Colombia.

The objectives of this study were to determine Brucella canis seroprevalence in dogs and in humans living near kennels and to explore risk factors associated with seropositivity. Twenty kennels were included in a serological survey with RSAT-2ME, and samples were collected from 428 dogs and 91 humans. An interview was applied to determine risk factors, and the data were analyzed using logistic regression. Seroprevalence was 15% in dogs and 9% in humans. Factors associated with current canine seropositivity were: history of canine seropositivity, non-culling of seropositive dogs, history of abortion, poor hygiene and personal protection during reproductive service, and unsafe procedures during care for abortions. Protective factors included: rural location of kennels, ease of cleaning kennels, pre-mating RSAT-2ME, and safe procedures during care for delivery. Factors associated with seropositive status in humans were: kennels located in Valle de Aburrá and urban location.

Factores asociados con la seropositividad a Brucella canis en criaderos caninos de dos regiones de Antioquia, Colombia / Factors associated with Brucella canis seropositivity in kennels of two regions of Antioquia, Colombia / Fatores associados à soropositividade por Brucella canis em cães reprodutores em duas regiões no Estado de Antioquia, Colômbia

El objetivo fue determinar la seroprevalencia a Brucella canis en perros y humanos convivientes en criaderos caninos y explorar los factores de riesgo asociados a la seropositividad. Se tomaron 20 criaderos, en los cuales se realizó diagnóstico serológico por PARP-2ME de 428 caninos y 91 humanos. Se aplicó una encuesta para determinar los factores de riesgo y se analizaron los datos mediante regresión logística. Se determinó una seroprevalencia de 15% en caninos y 9% en humanos convivientes. Se determinaron como factores asociados a la seropositividad canina el historial de seropositividad canina, conservar los caninos seropositivos, historial de aborto, higiene y protección del operario deficientes durante el servicio reproductivo, y procedimiento inseguro durante la atención de abortos. Como factores protectores se establecieron la ubicación rural de los criaderos, facilidad de aseo de los caniles, PARP-2ME premonta, y procedimiento seguro durante la atención de partos. En humanos se determinaron factores asociados: criaderos ubicados en el Valle Aburrá y de tipo urbano.

The objectives of this study were to determine Brucella canis seroprevalence in dogs and in humans living near kennels and to explore risk factors associated with seropositivity. Twenty kennels were included in a serological survey with RSAT-2ME, and samples were collected from 428 dogs and 91 humans. An interview was applied to determine risk factors, and the data were analyzed using logistic regression. Seroprevalence was 15% in dogs and 9% in humans. Factors associated with current canine seropositivity were: history of canine seropositivity, non-culling of seropositive dogs, history of abortion, poor hygiene and personal protection during reproductive service, and unsafe procedures during care for abortions. Protective factors included: rural location of kennels, ease of cleaning kennels, pre-mating RSAT-2ME, and safe procedures during care for delivery. Factors associated with seropositive status in humans were: kennels located in Valle de Aburrá and urban location.

O objetivo desta pesquisa foi determinar a soroprevalência de brucelose dada por Brucella canis na população canina e os seres humanos que moram junto com os cães reprodutores, e explorar os fatores de risco associados à soropositividade.Vinte cães foram amostrados, nestes se fez o diagnóstico sorológico por PARP-2ME para 428 caninos e 91 pessoas. Para o estudo de fatores de risco associados à doença foi realizada uma análise por regressão logística. Encontrou-se uma soroprevalência de 15% e 9% nos caninos e humanos, respectivamente. Foram identificados como fatores de risco associados à soropositividade canina nos canis avaliados a história clínica com antigos diagnósticos de abortos e de soropositividade, conservar caninos que sejam soropositivos, a má higiene no canil e uma indumentária laboral insuficiente para o trabalhador que mexe com os cães, tanto durante o serviço reprodutivo quanto na atenção de abortos que possam ser inseguros. Encontraram-se como fatores de proteção nesta pesquisa as regiões rurais onde estava a incubadora, a facilidade de limpeza que possibilita uma melhor higiene dos canis, PARP-2ME pré-nupcial e procedimento seguro durante o parto. Em humanos foram determinados como fatores associados: criadores localizados no Valle Aburrá e do tipo urbano.

The vaccine candidate BLSOmp31 protects mice against Brucella canis infection.

Canine brucellosis represents a major reproductive problem worldwide and it is considered a zoonotic disease. New approaches are therefore urgently needed to develop an effective and safe immunization strategy against Brucella canis. In the present study, BALB/c mice were subcutaneously immunized with the recombinant chimera rBLSOmp31 formulated in different adjuvants. The different strategies induced a vigorous immunoglobulin G (IgG) response, with high titers of IgG1 as well as IgG2. Besides, spleen cells from rBLSOmp31-immunized mice produced gamma interferon and IL-4, suggesting the induction of a mixed Th1-Th2. Vaccination with rBLSOmp31-IFA formulation provided the best protection levels comparable with that given by control vaccines. None of the immunization strategies induced serological interference in diagnosis. Hitherto, this is the first report that a recombinant vaccine confers protection against B. canis in mice.

Detección de Brucella canis por método de inmunocromatografía en perros vagos capturados en la ciudad de Temuco, Chile, 2011 / Detection of Brucella canis by immunochromatography method in vague dogs captured in Temuco city, Chile, 2011

Background: Brucella canis is responsible for brucellosis in dogs, causing reproductive disorders and is considered a zoonoses, as described in several countries. The epidemiological data are scarce in our country. Aim: To determine the prevalence of Brucella canis in vague dogs in Temuco city and housed in the Temuco Kennel. Methods: Quantitative and cross-section study. We used 400 samples of dogs of both sexes, different ages and mainly mixed race, which were tested by immunochromatography. Results: Antibodies were detected in 4 samples Brucella canis which represented 1% of the population studied, 2 females (0.5%) and 2 males (0.5%). Discussion: We conclude that dogs are infected by B. canis in a low range but remains a risk condition to the health of the human population if not maintained adequate sanitary control of pets, like vague dogs.

Introducción: Brucella canis es responsable de la brucelosis en perros, provocándoles trastornos reproductivos y es considerada una zoonosis, ya descrita en varios países. Los datos epidemiológicos en nuestro medio son exiguos. Objetivo: Determinar la prevalencia de B. canis en perros vagos capturados en la ciudad de Temuco y albergados en el Canil Temuco. Materialy Métodos: Estudio de tipo cuantitativo y de corte transversal. Se utilizaron 400 muestras de perros de ambos sexos, diferentes edades y principalmente mestizos, procesadas mediante la prueba de inmunocromatografía. Resultados: Se detectaron anticuerpos anti-B. canis en 4 muestras lo cual representó 1% de la población estudiada, 2 hembras (0,5%) y 2 machos (0,5%). Conclusión: El hallazgo de perros serológicamente positivos a B. canis, es baja pero no deja de ser un indicador del riesgo en el que se encuentra la salud de la población humana si no se mantiene un adecuado control sanitario de las mascotas, como ocurre con los perros vagos.

Serological trail of Brucella infection in an urban slum population in Brazil.

INTRODUCTION: Brucellosis is a re-emerging zoonosis with new cases reported each year in many Latin American countries, but it is mostly under-recognized. This study presents a serological investigation of infection with Brucella abortus and Brucella canis in a poor urban community in the city of Salvador, Brazil. METHODOLOGY: Human sera (n = 180) were randomly selected from 3,171 samples taken from healthy individuals during 2003-2004 and tested with C-ELISA for B. abortus and I-ELISA for B. canis. RESULTS: Thirteen percent (24/180) of the individuals were positive for B. abortus and 4.6 % (8/174) were positive for B. canis. Among the variables studied only age (older than 45 years) appeared to be a risk factor for the detection of Brucella antibodies. CONCLUSION: These results indicate the presence of Brucella infection in this settlement and highlight the need to understand the epidemiology of infection under these circumstances to establish the necessary measures for surveillance and control.

Serologic survey of brucellosis in captive neotropical wild carnivores in northeast Brazil.

Abstract. This study reports the detection of antibodies against Brucella abortus and B. canis in wild neotropical carnivores kept in captivity in three zoos in northeastern Brazil. A total of 42 serum samples were examined, 17 from coatis (Nasua nasua), eight from crab-eating raccoons (Procyon cancrivorus), three from crab-eating foxes (Cerdocyon thous), three from hoary foxes (Lycalopex vetulus), two from little spotted cats (Leopardus tigrinus), five from tayras (Eira barbara), two from greater grisons (Galictis vittata), and two from neotropical river otters (Lontra longicaudis). The Rose-Bengal test and complement fixation test (CFT) were performed to detect anti-Brucella spp. antibodies, whereas the agar gel immunodiffusion test (AGID) was employed to detect anti-B. canis antibodies. The overall seroprevalence varied by species and by test; in addition, CFT and AGID seemed better able to detect antibodies against B. abortus and B. canis, respectively. This is the first study on the presence of anti-Brucella spp. antibodies in captive carnivores from Brazil, as well as the first report of antibodies to Brucella spp. in coatis, crab-eating raccoons, hoary foxes, little spotted cats, tayras, and greater grisons.

Brucella canis infection in dogs attended in veterinary clinics from patos, Paraíba state, Brazil

To determine the frequency of anti-Brucella canis antibodies in dogs attended in veterinary clinics from Patos, Paraíba State, Brazil, as well as to identify risk factors and to isolate and identify the agent, 193 dogs were used. Agar gel immunodiffusion test (AGID) was used to detect B. canis antibodies in sera. Isolation of B. canis was carried out in blood and bone marrow from seropositive animals. Six animals tested seropositive in AGID, resulting in a frequency of 3.11 percent. B. canis was isolated from bone marrow of one seropositive animal, with confirmation by PCR. Lack of cleaning of the dog's environment was identified as risk factor (odds ratio = 7.91). This is the first report of isolation of B. canis in dogs from the Northeast region of Brazil.

Validation of an ELISA method for the serological diagnosis of canine brucellosis due to Brucella canis.

In the present study, the validation of an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of canine brucellosis is described. Two different antigenic extracts, obtained by heat or ultrasonic homogenization of microbial antigens from a wild isolate of Brucella canis bacteria, were compared by ELISA and Western blot (WB). A total of 145 canine sera were used to define sensitivity, specificity and accuracy of the ELISA as follows: (1) sera from 34 animals with natural B. canis infection, confirmed by blood culture and PCR, as well as 51 sera samples from healthy dogs with negative results by the agar-gel immunodiffusion (AGID) test for canine brucellosis, were used as the control panel for B. canis infection; and (2) to scrutinize the possibility of cross reactions with other common dog infections in the same geographical area in Brazil, 60 sera samples from dogs harboring known infections by Leptospira sp., Ehrlichia canis, canine distemper virus (CDV), Neospora caninum, Babesia canis and Leishmania chagasi (10 in each group) were included in the study. The ELISA using heat soluble bacterial extract (HE-antigen) as antigen showed the best values of sensitivity (91.18%), specificity (100%) and accuracy (96.47%). In the WB analyses, the HE-antigen showed no cross-reactivity with sera from dogs with different infections, while the B. canis sonicate had various protein bands identified by those sera. The performance of the ELISA standardized with the heat soluble B. canis antigen indicates that this assay can be used as a reliable and practical method to confirm infection by this microorganism, as well as a tool for seroepidemiological studies.

The feasibility of using antigens prepared with rough Brucella strains for diagnosis of canine brucellosis.

Clinical diagnosis of canine brucellosis is not sensitive enough and a negative blood culture cannot rule out the disease. Indirect methods of serological testing such as agar gel immunodiffusion (AGID), rapid slide agglutination test (RSAT) and indirect enzyme linked immunoassay (IELISA) are preferred for routine diagnosis. Since Brucella canis shares antigenic components with the Brucella ovis and Brucella abortus RB51 strain, it would seem that either strain could be used as antigen. We present data on AGID and IELISA tests using the B. ovis antigen, RSAT and IELISA using the B. canis antigen and IELISA using the B. abortus RB51 antigen. The cut-off values were adjusted by the ROC analysis; the IELISA-B. ovis cut-off value was 23 (%P) and the IELISA-B. abortus RB51, 24 (%P), with 100% sensitivity and 98.8% specificity. RSAT detected 100% of positive cases, while AGID was less sensitive. The sera from dogs treated with antibiotic showed that %P correlated well with the clinical course. Sera from dogs presumptively infected with B. suis were negative in all tests performed with the rough Brucella strains. RSAT is a very sensitive screening test and IELISA-B. canis, B. ovis and B. abortus RB51 could be used as confirmatory tests, since they show good specificity and sensitivity.

Human Brucella canis outbreak linked to infection in dogs.

The zoonotic risk of Brucella canis has been considered fairly high for persons who handle breeding dogs in kennels or are exposed to infected animals. Transmission to humans in other circumstances has been thought to be rare. We describe an uncommon outbreak of brucellosis caused by B. canis which, to the best of our knowledge, is the first reported in the literature. This outbreak involved six persons (three children and three adults), a bitch and three puppies which had close daily contact with the family. The clinical symptoms of the index case led to an erroneous diagnosis and the infection would have gone undiagnosed if culture had not been positive. This report aims to increase awareness of medical personnel of the need to order screening tests for children, immunodeficient persons or pregnant women presenting with fever of unknown origin, unexplained spleen or liver enlargement or other systemic signs. The emerging zoonotic potential of this disease in urban areas and the need to coordinate canine brucellosis surveillance systems should be evaluated.

A serological and bacteriological survey of dogs to detect Brucella infection in Lomas de Zamora, Buenos Aires province.

Canine brucellosis caused by Brucella canis is a disease of the reproductive tract that may cause miscarriage in females, infection of the sexual organs in males and infertility in both sexes. The prevalence of brucellosis in dogs is unknown and little has been done to control the disease, except in certain breeds and some commercial dog kennels. In the course of a free neuter program in Lomas de Zamora, Buenos Aires province, prevalence of antibodies to Brucella sp., bacteriological isolation and clinical observations were performed. Of 224 dogs studied, 33 (14.7%) were found positive for the rapid slide agglutination test (RSAT), 24 (10.7%) of which were confirmed by IELISA. Of the 33 RSAT positive, 17 (51.5%) blood cultures were done, and B. canis were isolated from 2 cases. Since infected dogs have been shown to remain bacteremic for prolonged periods, our results also suggest a risk of human infections in this area.

[Canine brucellosis in dogs in the city of Buenos Aires]. / Brucelosis canina en perros de la ciudad de Buenos Aires.

Canine brucellosis, caused by Brucella canis, provokes epidydimitis, testicular atrophy and sterility in male dogs, while in females the major symptom is miscarriage. Transmission to humans may be through contact with semen, urine and/or aborted fetuses of infected animals. Our study, observational and cross-sectional, focused on dogs in lower class neighborhoods and slums with a high rate of unmet basic needs (UBN) in 8 areas of the city of Buenos Aires. We studied 219 dogs: 184 females and 35 males, that tested negative to the buffered plate antigen test (BPAT), which ruled out infection with smooth species of Brucella. We detected anti-B. canis antibodies in 16 dogs (7.3%): 9 females and 7 males, relevant data since the urine of males is considered one of the vectors for the spread of the infection. Although we could run blood cultures on only 175 animals, we isolated B. canis in 3 (2 females and 1 male). Only 3 of the owners of dogs that tested positive consented to a serological diagnosis and two of them were positive. We highlight that the agar gel immunodiffusion test (IGID) proved to have low sensitivity, having detected only one of the 16 positive cases and none of the three confirmed by isolation. We conclude that in the areas studied, the detection of serologically positive dogs and the isolation of B. canis in 3 cases are indicators of the health hazard for the population exposed to it.

Brucelosis canina en perros de la ciudad de Buenos Aires / Canine brucellosis in dogs in the city of Buenos Aires

La brucelosis canina, causada por Brucella canis, provoca epididimitis, atrofia testicular y esterilidad en los perros, mientras que en las hembras el síntoma principal es el aborto. La transmisión al hombre puede ser por contacto con el semen, orina, y/o fetos abortados de animales infectados. El presente estudio de tipo observacional de corte transversal, se realizó en caninos de barrios y asentamientos con alto índice de necesidades básicas insatisfechas (NBI) en 8 áreas de la ciudad de Buenos Aires. Se estudiaron 219 perros, 184 hembras y 35 machos, que fueron negativos a la prueba de aglutinación con antígeno tamponado (BPAT), que descartó la infección con especies lisas del género Brucella. Sedetectaron anticuerpos anti-B. canis en 16 perros (7.3%), 9 hembras y 7 machos, este último dato es relevante ya que la orina de los machos es considerada uno de los medios de diseminación de la infección. Aunque sólo se pudieron tomar hemocultivos a 175 animales, en 3 (2 hembras y un macho) se aislaron B. canis. Sólo 3 de los dueños de los perros positivos accedieron al diagnóstico serológico y dos resultaron positivos. Destacamos que la prueba de inmunodifusión en gel de agar (IGDA) ha demostrado ser poco sensible, detectó sólo uno de los 16 casos positivos y ninguno de los tres confirmados por aislamiento. Concluimos que en las áreas estudiadas el hallazgo de perros serológicamente positivos y el aislamiento de B. canis en 3 casos, son indicadores del riesgo en el que se encuentra la salud de la población expuesta.

Canine brucellosis, caused by Brucella canis, provokes epidydimitis, testicular atrophy and sterility in male dogs, while in females the major symptom is miscarriage. Transmission to humans may be through contact with semen, urine and/or aborted fetuses of infected animals. Our study, observational and cross-sectional, focused on dogs in lower class neighborhoods and slums with a high rate of unmet basic needs (UBN) in 8 areas of the city of Buenos Aires. We studied 219 dogs: 184 females and 35 males, that tested negative to the buffered plate antigen test (BPAT), which ruled out infection with smooth species of Brucella. We detected anti-B. canis antibodies in 16 dogs (7.3%): 9 females and 7 males, relevant data since the urine of males is considered one of the vectors for the spread of the infection. Although we could run blood cultures on only 175 animals, we isolated B. canis in 3 (2 females and 1 male). Only 3 of the owners of dogs that tested positive consented to a serological diagnosis and two of them were positive. We highlight that the agar gel immunodiffusion test (IGID) proved to have low sensitivity, having detected only one of the 16 positive cases and none of the three confirmed by isolation. We conclude that in the areas studied, the detection of serologically positive dogs and the isolation of B. canis in 3 cases are indicators of the health hazard for the population exposed to it.